On Sun, Dec 07, 2003 at 10:00:07PM +0100, Chris Liechti wrote: > Chris Howard wrote: > > What I want to build is a little card that will > > output three different sub-audible tones, 100hz, > > 123hz, and another similar one. I would like three > > if "sub-audible" means that the human ear cant hear it then i have to > say that those frequenciey are clearly _not_ sub-audible. but it may be > that your kenwood transeiver has a band pass built in, so that it does > not transmit those low frequecies, or the receiver does filter them.
I think the official name for them is CTCSS tones. Many repeater systems require them. > > yes, timer a or b in PWM mode is well suited to generate tones. > that way you can program the frequency in CCR0 and set CCR1 = CCR0/2 for > a symmetric square output signal. you can also add a RC lowpass at the > output to filer out the harmonics. Thanks! -- Chris Howard YipYap.Com ch...@yipyap.com Estes Park, Colorado USA current Estes Park weather -- http://www.yipyap.com/wscurrent.html
